"Ken G." <beach...@insightbb.com> wrote
In using Geany, I have the ability to complied a Python program. For
example, I can complied "program.py" to program.pyc."
You compile (note spelling) a python script everytime you import it
(if it has not already been compiled).
If you compile a new(or changed) script Python first compiles the
source text into an intermediate version called byte code (sometimes
called p-code) that the interpreter can understand and execute. It
saves the byte-code as a .pyc file so that in future it can import
the compiled version directly (if there is no newer .py file).
This byte-code is similar to what Java produces when you comile jave
into a class file. The Jave runtime engine is basically an interpreter
for Java byte-code. .Net code follows a similar approach too.
What is the purpose of a complied Python program? Can it be transported
to another computer without Python installed as run as it is?
No, it needs Python to run it but it can be transported without
the .py file existing - which gives a minimal amount of code
hiding and a marginal startup advantage the first time you run it.
Its not usually worth it IMHO.
You can see the p-code if you use the dis module. The docs give this
example:
def myfunc(alist):
... return len(alist)
...>>> dis.dis(myfunc)
2 0 LOAD_GLOBAL 0 (len)
3 LOAD_FAST 0 (alist)
6 CALL_FUNCTION 1
9 RETURN_VALUE
The bytecode : 0,0,3,0,6,1,9 is more compact but much more primitive than
the original source text. It is similasr in character to a machine code
program but is machine independant.Thus it is said to run on a virtual
machine - the Python interpreter.HTH,-- Alan GauldAuthor of the Learn to
Program web sitehttp://www.alan-g.me.uk/
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